Text C. MAN THE LOSER?

The warming of the climate on Earth that could only be reg­istered by experts at the begin­ning of the century is obvious to everybody in our day. The process has been set off by the rising content of carbon dioxide in the atmosphere and is directly traceable to human activity: the burning of fuels, the spewing of industrial exhausts, the felling of forests, and erosion of farmlands. However, some of the carbon dioxide is effectively absorbed from the air by the ocean and the green plants on land. Who will win in this "competition" be­tween Man and Nature? What will happen to the global cli­mate in a longer run, beyond the turn of this century?

A mathematical model has been developed by some em­ployees of the Computer Centre of the Russian Academy of Sciences in an at­tempt to answer these ques­tions. The model is described by a system of 1,500 differen­tial equations using such vari­ables as amounts of carbon dioxide in the biomass of living plants and in humus. To obtain accurate results, the scholars divided the land mass on the geographical map into meshes measuring 4 by 5 degrees. They have taken in the mean annual temperature, rainfall, and plant production over the year, since these characteris­tics are influenced by the car­bon dioxide content in the at­mosphere. The analysis has been carried out for such re­gions as Europe, the tropical forests, Canada, the USA, and this country since 1860 and has been extended till the year 2000.

It turned out that carbon dioxide is absorbed in all the regions, the forests in the tem­perate zone of the Northern Hemisphere playing the most significant role in the process. However, up to 53 percent of carbon dioxide contributed by industrial exhausts remains in the atmosphere (in the tropical forest zone the figure is con­siderably lower, while in the temperate and northern re­gions it is rising continuously). Apparently, plants can no longer absorb these excessive amounts of carbon dioxide. According to some estimates, the capability of green plants on land to absorb carbon dioxide declined after 2000, and at some point be­tween 2000 and 2030 the land itself may become a source of carbon dioxide!

When this will happen, if at all, depends on many factors, in the first place, on the eco­logical strategy of mankind which appears to be climbing further out on to the limb.

A. Tarko, B. Bogatyrev, and A, Kirilenko, "The Role of Countries and Regions in the Formation of the Global Carbon Budget in the Atmosphere", Doklady Akademit Nauk, 1992, Vol. 322, No. 2 (in Russian).

I. Read the text ‘ Man the Loser?’ Find in the text the information about a mathematical model developed by the Computer Centre of the Russian Academy of Sciences. What purpose is it designed for?

II. Describe the mathematical model developed by some employees of the Computer Centre of the Russian Academy of Sciences. You may do it either in Russian or in English.

III. Speak on the results of the investigation (either in Russian or in English).

IV. Suggest another headline for text C.

C o n v e r s a t i o n

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